A survey by the 2013 Tara Oceans circumpolar expedition, published in Science Advances, has found that the Arctic Ocean is a “dead end” for plastic dumped into the North Atlantic off Europe and North America.
The expedition to the Arctic Ocean – on-board Tara, their research vessel – was the final stage in a mission to map floating plastic pollution in the world’s oceans. They sampled 42 Arctic sites with nets, collecting floating plastic debris that included fishing lines and a variety of plastic films, fragments and granules.
The study found that most of the surface waters in the Arctic Polar Circle were only slightly polluted with plastic debris, but the Greenland and Barents Seas were heavily polluted. They found hundreds of thousands of small bits of plastic per square mile, and a great deal more is expected to be lying on the seafloor. Overall, they estimate that these seas have accumulated hundreds of tons of debris, composed of roughly 300 billion tiny pieces of plastic.
The reason for the vast amount of plastic in the Arctic is due to ocean currents, which carries waste up to the region. This was verified by the proportion of film-type plastic (plastic bags, label, packaging, etc). The researchers also monitored the pathway of plastic in the North Atlantic Ocean by using 17,000 satellite buoys. This confirmed the poleward flow of pollution via thermaline circulation, which is a current known as the global ocean conveyer belt. Upon reaching the Arctic, the current sinks back towards the equator, but the plastic does not sink with it and so accumulates at this “dead end”.
The results illustrate the need to properly manage litter at its source, since upon entering the ocean, our waste can end up in faraway oceans. It highlights our collective responsibility for the damage caused to the oceans: Waste dumped by one country can be carried by currents to a place half a world away and threaten its fragile marine ecosystem. Plastic waste is a detrimental issue – marine organisms are poisoned when they mistakenly eat it, and they can become tangled in floating plastic, which can kill them.
It may be the case that floating plastic in the Arctic only accounts for less than three percent of the global total (according to the study), but the findings show that plastic will continue to accumulate in the region as it is carried up from lower latitudes.
The authors stress the serious effect of this pollution on the Arctic’s unique ecosystem and encourage people to take responsibility and make a change.
The team behind the study involves researchers from eight different countries. It is led by Professor Andrés Cózar from the University of Cadiz in Spain, as well as Dr. Erik van Sebille from the Grantham Institute at Imperial College London.
Check out Tara Expeditions’ website to read up on the work they do in studying the impacts of climate change and the threats to our oceans: www.taraexpeditions.org.
© Images and infographics courtesy of the Tara Expeditions Foundation